X-Git-Url: http://git.indexdata.com/?a=blobdiff_plain;f=src%2Frelevance.c;h=74f0e155f8628a7a40bb2b4b00317519f2796e38;hb=7895ed928aac63bc69f3ee778d80335fb3c605ed;hp=87f5b24991426947a29c3bcb64809da615a89851;hpb=ed7a00b666a5ef705687a25e858b561e2b28ca5b;p=pazpar2-moved-to-github.git

diff --git a/src/relevance.c b/src/relevance.c
index 87f5b24..74f0e15 100644
--- a/src/relevance.c
+++ b/src/relevance.c
@@ -1,5 +1,5 @@
 /* This file is part of Pazpar2.
-   Copyright (C) 2006-2012 Index Data
+   Copyright (C) 2006-2013 Index Data
 
 Pazpar2 is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free
@@ -28,58 +28,194 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #include "relevance.h"
 #include "session.h"
 
+#ifdef WIN32
+#define log2(x) (log(x)/log(2))
+#endif
+
 struct relevance
 {
     int *doc_frequency_vec;
+    int *term_frequency_vec_tmp;
+    int *term_pos;
     int vec_len;
     struct word_entry *entries;
     pp2_charset_token_t prt;
+    int rank_cluster;
+    double follow_factor;
+    double lead_decay;
+    int length_divide;
     NMEM nmem;
 };
 
 struct word_entry {
     const char *norm_str;
+    const char *display_str;
     int termno;
+    char *ccl_field;
     struct word_entry *next;
 };
 
-int word_entry_match(struct word_entry *entries, const char *norm_str)
+static struct word_entry *word_entry_match(struct relevance *r,
+                                           const char *norm_str,
+                                           const char *rank, int *weight)
 {
-    for (; entries; entries = entries->next)
+    int i = 1;
+    struct word_entry *entries = r->entries;
+    for (; entries; entries = entries->next, i++)
     {
-        if (!strcmp(norm_str, entries->norm_str))
-            return entries->termno;
+        if (*norm_str && !strcmp(norm_str, entries->norm_str))
+        {
+            const char *cp = 0;
+            int no_read = 0;
+            sscanf(rank, "%d%n", weight, &no_read);
+            rank += no_read;
+            while (*rank == ' ')
+                rank++;
+            if (no_read > 0 && (cp = strchr(rank, ' ')))
+            {
+                if ((cp - rank) == strlen(entries->ccl_field) &&
+                    memcmp(entries->ccl_field, rank, cp - rank) == 0)
+                    *weight = atoi(cp + 1);
+            }
+            return entries;
+        }
     }
     return 0;
 }
 
+int relevance_snippet(struct relevance *r,
+                      const char *words, const char *name,
+                      WRBUF w_snippet)
+{
+    int no = 0;
+    const char *norm_str;
+    int highlight = 0;
+
+    pp2_charset_token_first(r->prt, words, 0);
+    while ((norm_str = pp2_charset_token_next(r->prt)))
+    {
+        size_t org_start, org_len;
+        struct word_entry *entries = r->entries;
+        int i;
+
+        pp2_get_org(r->prt, &org_start, &org_len);
+        for (; entries; entries = entries->next, i++)
+        {
+            if (*norm_str && !strcmp(norm_str, entries->norm_str))
+                break;
+        }
+        if (entries)
+        {
+            if (!highlight)
+            {
+                highlight = 1;
+                wrbuf_puts(w_snippet, "<match>");
+                no++;
+            }
+        }
+        else
+        {
+            if (highlight)
+            {
+                highlight = 0;
+                wrbuf_puts(w_snippet, "</match>");
+            }
+        }
+        wrbuf_xmlputs_n(w_snippet, words + org_start, org_len);
+    }
+    if (highlight)
+        wrbuf_puts(w_snippet, "</match>");
+    if (no)
+    {
+        yaz_log(YLOG_DEBUG, "SNIPPET match: %s", wrbuf_cstr(w_snippet));
+    }
+    return no;
+}
+
 void relevance_countwords(struct relevance *r, struct record_cluster *cluster,
-                          const char *words, int multiplier, const char *name)
+                          const char *words, const char *rank,
+                          const char *name)
 {
-    int *mult = cluster->term_frequency_vec_tmp;
+    int *w = r->term_frequency_vec_tmp;
     const char *norm_str;
     int i, length = 0;
+    double lead_decay = r->lead_decay;
+    struct word_entry *e;
+    WRBUF wr = cluster->relevance_explain1;
+    int printed_about_field = 0;
 
     pp2_charset_token_first(r->prt, words, 0);
-    for (i = 1; i < r->vec_len; i++)
-        mult[i] = 0;
+    for (e = r->entries, i = 1; i < r->vec_len; i++, e = e->next)
+    {
+        w[i] = 0;
+        r->term_pos[i] = 0;
+    }
 
+    assert(rank);
     while ((norm_str = pp2_charset_token_next(r->prt)))
     {
-        int res = word_entry_match(r->entries, norm_str);
-        if (res)
+        int local_weight = 0;
+        e = word_entry_match(r, norm_str, rank, &local_weight);
+        if (e)
         {
+            int res = e->termno;
+            int j;
+
+            if (!printed_about_field)
+            {
+                printed_about_field = 1;
+                wrbuf_printf(wr, "field=%s content=", name);
+                if (strlen(words) > 50)
+                {
+                    wrbuf_xmlputs_n(wr, words, 49);
+                    wrbuf_puts(wr, " ...");
+                }
+                else
+                    wrbuf_xmlputs(wr, words);
+                wrbuf_puts(wr, ";\n");
+            }
             assert(res < r->vec_len);
-            mult[res] += multiplier;
+            w[res] += local_weight / (1 + log2(1 + lead_decay * length));
+            wrbuf_printf(wr, "%s: w[%d] += w(%d) / "
+                         "(1+log2(1+lead_decay(%f) * length(%d)));\n",
+                         e->display_str, res, local_weight, lead_decay, length);
+            j = res - 1;
+            if (j > 0 && r->term_pos[j])
+            {
+                int d = length + 1 - r->term_pos[j];
+                wrbuf_printf(wr, "%s: w[%d] += w[%d](%d) * follow(%f) / "
+                             "(1+log2(d(%d));\n",
+                             e->display_str, res, res, w[res],
+                             r->follow_factor, d);
+                w[res] += w[res] * r->follow_factor / (1 + log2(d));
+            }
+            for (j = 0; j < r->vec_len; j++)
+                r->term_pos[j] = j < res ? 0 : length + 1;
         }
         length++;
     }
 
-    for (i = 1; i < r->vec_len; i++)
+    for (e = r->entries, i = 1; i < r->vec_len; i++, e = e->next)
     {
-        if (length > 0) /* only add if non-empty */
-            cluster->term_frequency_vecf[i] += (double) mult[i] / length;
-        cluster->term_frequency_vec[i] += mult[i];
+        if (length == 0 || w[i] == 0)
+            continue;
+        wrbuf_printf(wr, "%s: tf[%d] += w[%d](%d)", e->display_str, i, i, w[i]);
+        switch (r->length_divide)
+        {
+        case 0:
+            cluster->term_frequency_vecf[i] += (double) w[i];
+            break;
+        case 1:
+            wrbuf_printf(wr, " / log2(1+length(%d))", length);
+            cluster->term_frequency_vecf[i] +=
+                (double) w[i] / log2(1 + length);
+            break;
+        case 2:
+            wrbuf_printf(wr, " / length(%d)", length);
+            cluster->term_frequency_vecf[i] += (double) w[i] / length;
+        }
+        cluster->term_frequency_vec[i] += w[i];
+        wrbuf_printf(wr, " (%f);\n", cluster->term_frequency_vecf[i]);
     }
 
     cluster->term_frequency_vec[0] += length;
@@ -89,6 +225,7 @@ static void pull_terms(struct relevance *res, struct ccl_rpn_node *n)
 {
     char **words;
     int numwords;
+    char *ccl_field;
     int i;
 
     switch (n->kind)
@@ -106,6 +243,8 @@ static void pull_terms(struct relevance *res, struct ccl_rpn_node *n)
         {
             const char *norm_str;
 
+            ccl_field = nmem_strdup_null(res->nmem, n->u.t.qual);
+
             pp2_charset_token_first(res->prt, words[i], 0);
             while ((norm_str = pp2_charset_token_next(res->prt)))
             {
@@ -114,7 +253,9 @@ static void pull_terms(struct relevance *res, struct ccl_rpn_node *n)
                     e = &(*e)->next;
                 *e = nmem_malloc(res->nmem, sizeof(**e));
                 (*e)->norm_str = nmem_strdup(res->nmem, norm_str);
+                (*e)->ccl_field = ccl_field;
                 (*e)->termno = res->vec_len++;
+                (*e)->display_str = nmem_strdup(res->nmem, words[i]);
                 (*e)->next = 0;
             }
         }
@@ -123,23 +264,47 @@ static void pull_terms(struct relevance *res, struct ccl_rpn_node *n)
         break;
     }
 }
+void relevance_clear(struct relevance *r)
+{
+    if (r)
+    {
+        int i;
+        for (i = 0; i < r->vec_len; i++)
+            r->doc_frequency_vec[i] = 0;
+    }
+}
 
 struct relevance *relevance_create_ccl(pp2_charset_fact_t pft,
-                                       NMEM nmem, struct ccl_rpn_node *query)
+                                       struct ccl_rpn_node *query,
+                                       int rank_cluster,
+                                       double follow_factor, double lead_decay,
+                                       int length_divide)
 {
+    NMEM nmem = nmem_create();
     struct relevance *res = nmem_malloc(nmem, sizeof(*res));
-    int i;
 
     res->nmem = nmem;
     res->entries = 0;
     res->vec_len = 1;
+    res->rank_cluster = rank_cluster;
+    res->follow_factor = follow_factor;
+    res->lead_decay = lead_decay;
+    res->length_divide = length_divide;
     res->prt = pp2_charset_token_create(pft, "relevance");
-    
+
     pull_terms(res, query);
 
     res->doc_frequency_vec = nmem_malloc(nmem, res->vec_len * sizeof(int));
-    for (i = 0; i < res->vec_len; i++)
-        res->doc_frequency_vec[i] = 0;        
+
+    // worker array
+    res->term_frequency_vec_tmp =
+        nmem_malloc(res->nmem,
+                    res->vec_len * sizeof(*res->term_frequency_vec_tmp));
+
+    res->term_pos =
+        nmem_malloc(res->nmem, res->vec_len * sizeof(*res->term_pos));
+
+    relevance_clear(res);
     return res;
 }
 
@@ -148,35 +313,40 @@ void relevance_destroy(struct relevance **rp)
     if (*rp)
     {
         pp2_charset_token_destroy((*rp)->prt);
+        nmem_destroy((*rp)->nmem);
         *rp = 0;
     }
 }
 
+void relevance_mergerec(struct relevance *r, struct record_cluster *dst,
+                        const struct record_cluster *src)
+{
+    int i;
+
+    for (i = 0; i < r->vec_len; i++)
+        dst->term_frequency_vec[i] += src->term_frequency_vec[i];
+
+    for (i = 0; i < r->vec_len; i++)
+        dst->term_frequency_vecf[i] += src->term_frequency_vecf[i];
+}
+
 void relevance_newrec(struct relevance *r, struct record_cluster *rec)
 {
-    if (!rec->term_frequency_vec)
-    {
-        int i;
+    int i;
 
-        // term frequency [1,..] . [0] is total length of all fields
-        rec->term_frequency_vec =
-            nmem_malloc(r->nmem,
-                        r->vec_len * sizeof(*rec->term_frequency_vec));
-        for (i = 0; i < r->vec_len; i++)
-            rec->term_frequency_vec[i] = 0;
-        
-        // term frequency divided by length of field [1,...]
-        rec->term_frequency_vecf =
-            nmem_malloc(r->nmem,
-                        r->vec_len * sizeof(*rec->term_frequency_vecf));
-        for (i = 0; i < r->vec_len; i++)
-            rec->term_frequency_vecf[i] = 0.0;
-        
-        // for relevance_countwords (so we don't have to xmalloc/xfree)
-        rec->term_frequency_vec_tmp =
-            nmem_malloc(r->nmem,
-                        r->vec_len * sizeof(*rec->term_frequency_vec_tmp));
-    }
+    // term frequency [1,..] . [0] is total length of all fields
+    rec->term_frequency_vec =
+        nmem_malloc(r->nmem,
+                    r->vec_len * sizeof(*rec->term_frequency_vec));
+    for (i = 0; i < r->vec_len; i++)
+        rec->term_frequency_vec[i] = 0;
+
+    // term frequency divided by length of field [1,...]
+    rec->term_frequency_vecf =
+        nmem_malloc(r->nmem,
+                    r->vec_len * sizeof(*rec->term_frequency_vecf));
+    for (i = 0; i < r->vec_len; i++)
+        rec->term_frequency_vecf[i] = 0.0;
 }
 
 void relevance_donerecord(struct relevance *r, struct record_cluster *cluster)
@@ -204,29 +374,52 @@ void relevance_prepare_read(struct relevance *rel, struct reclist *reclist)
             idfvec[i] = 0;
         else
         {
-            // This conditional may be terribly wrong
-            // It was there to address the situation where vec[0] == vec[i]
-            // which leads to idfvec[i] == 0... not sure about this
-            // Traditional TF-IDF may assume that a word that occurs in every
-            // record is irrelevant, but this is actually something we will
-            // see a lot
-            if ((idfvec[i] = log((float) rel->doc_frequency_vec[0] /
-                            rel->doc_frequency_vec[i])) < 0.0000001)
-                idfvec[i] = 1;
+            /* add one to nominator idf(t,D) to ensure a value > 0 */
+            idfvec[i] = log((float) (1 + rel->doc_frequency_vec[0]) /
+                            rel->doc_frequency_vec[i]);
         }
     }
     // Calculate relevance for each document
     while (1)
     {
-        int t;
         int relevance = 0;
+        WRBUF w;
+        struct word_entry *e = rel->entries;
         struct record_cluster *rec = reclist_read_record(reclist);
         if (!rec)
             break;
-        for (t = 1; t < rel->vec_len; t++)
+        w = rec->relevance_explain2;
+        wrbuf_rewind(w);
+        wrbuf_puts(w, "relevance = 0;\n");
+        for (i = 1; i < rel->vec_len; i++)
+        {
+            float termfreq = (float) rec->term_frequency_vecf[i];
+            int add = 100000 * termfreq * idfvec[i];
+
+            wrbuf_printf(w, "idf[%d] = log(((1 + total(%d))/termoccur(%d));\n",
+                         i, rel->doc_frequency_vec[0],
+                         rel->doc_frequency_vec[i]);
+            wrbuf_printf(w, "%s: relevance += 100000 * tf[%d](%f) * "
+                         "idf[%d](%f) (%d);\n",
+                         e->display_str, i, termfreq, i, idfvec[i], add);
+            relevance += add;
+            e = e->next;
+        }
+        if (!rel->rank_cluster)
+        {
+            struct record *record;
+            int cluster_size = 0;
+
+            for (record = rec->records; record; record = record->next)
+                cluster_size++;
+
+            wrbuf_printf(w, "score = relevance(%d)/cluster_size(%d);\n",
+                         relevance, cluster_size);
+            relevance /= cluster_size;
+        }
+        else
         {
-            float termfreq = (float) rec->term_frequency_vecf[t];
-            relevance += 100000 * (termfreq * idfvec[t] + 0.0000005);  
+            wrbuf_printf(w, "score = relevance(%d);\n", relevance);
         }
         rec->relevance_score = relevance;
     }